This was my first time out this year and first time pulling a skier since a head gasket replacement I did myself late last fall. It was a rough first go and I have some questions. Boat is '94 tbi.

1. I discovered oil leaking out between the intake manifold and the block. The location was below the distributor where the RTV creates the gasket. Does this mean I'll have to take the intake off again, get new gaskets, and try again?

There seems to be a decent sized gap between the maninfold and block that the RTV has to fill. Did I not get the manifold properly situated? Should it be metal to metal in that spot or a gap? I'll include a picture.

2. A separate issue, I was getting a decent amount of smoke coming out of the throttle body area when I lifted the motor box. My hope is that I just had some marvel mystery oil pooled from winterizing and it smoked when the engine warmed. Any other ideas? Should I worry. I'll post another pic.

3. The final issue. The boat started up just fine but we couldn't get it restarted after turning it off on the lake. I think it is the battery and I will have it tested. Just checking to see if the engine not turning over could have anything to do with the smoke (question#2)?

wtrskr

05-07-2011, 12:47 AM

This is the image of where the oil leak is occuring, right below the distributor through the RTV. Did I just not use enough RTV?

wtrskr

05-07-2011, 01:13 AM

The arrow points to where I think the smoke was coming from.

psychobilly

05-07-2011, 01:58 AM

I'm no motor guru but every motor I've ever seen has the two gaskets (metal with rubber on each head) and 2 flat rubber gaskets that lay on the block in the front and the back where you are showing in the first pic.

Watch this video about half way through are the rubber gaskets I'm speaking of. http://www.youtube.com/watch?v=qWcL5JrLWDk

At the end of the movie you can see where the intake is sitting on the motor and you can see the little flat ribbed rubber gaskets, I don't see them in your pic....

Bouyhead

05-07-2011, 07:02 AM

I don't use the gaskets provided for the manifold to block, I use Ultra Grey Sealant. Don't be shy with the stuff, put it on pretty thick and let it set up for several minutes before installing manifold, this way there is no issues with excess sealant falling into the motor.

66315

66316

Bouyhead

05-07-2011, 07:13 AM

Ultra Grey by Permatex

66317

JimN

05-07-2011, 09:27 AM

Help.

This was my first time out this year and first time pulling a skier since a head gasket replacement I did myself late last fall. It was a rough first go and I have some questions. Boat is '94 tbi.

1. I discovered oil leaking out between the intake manifold and the block. The location was below the distributor where the RTV creates the gasket. Does this mean I'll have to take the intake off again, get new gaskets, and try again?

There seems to be a decent sized gap between the maninfold and block that the RTV has to fill. Did I not get the manifold properly situated? Should it be metal to metal in that spot or a gap? I'll include a picture.

2. A separate issue, I was getting a decent amount of smoke coming out of the throttle body area when I lifted the motor box. My hope is that I just had some marvel mystery oil pooled from winterizing and it smoked when the engine warmed. Any other ideas? Should I worry. I'll post another pic.

3. The final issue. The boat started up just fine but we couldn't get it restarted after turning it off on the lake. I think it is the battery and I will have it tested. Just checking to see if the engine not turning over could have anything to do with the smoke (question#2)?

Your arrow is pointing at the IAC (Idle Air Control) and if you have smoke coming from there, it's possible that you have blow-by, That's not good but I would run it longer to see if it stops- could be from the work done to it. If it continues, do a compression and cylinder leak down test. If it doesn't stop and the leak down and compression tests indicate a problem, you'll have more work to do but since you seem to be pretty mechanically inclined, it's not the end of the world.

You posted that you couldn't re-start it- did it crank but not fire or did it not crank at all? Pull the plugs and see if oil or water are in the cylinders. Before you crank it, put a tarp or blanket over the floor and gunwale to keep anything from staining when the water or oil shoots out the next time you crank it.

It seems likely that the gasket(s) may not be correct or the surfaces aren't seating properly and, unfortunately, the manifold needs to come off again. Make sure the gasket set is for marine application. I always used FelPro and did use the rubber ones that came with the set. I made sure they were securely in place and then used black Permatex at the ends without problems but any good (meaning 'correct for the application) sealant will be fine as long as the surfaces are clean.

Did you re-use the head bolts? That's not recommended and could be part of the problem. Also, an accurate torque wrench makes it possible to do this without inconsistency and leaks.

wtrskr

05-07-2011, 10:40 AM

Thanks for the help. As far as being mechanically inclined, I don't have experience with engines but I'm willing to read up and give things a go. I Learned a lot last year doing the head gasket replacement.

I did use marine gaskets (skidim) and followed the shop manual for the torque specs etc. I also did re-use the head bolts. Maybe it was a bad idea but the manual said it was ok for my engine. Some of the engines use bolts that stretch but not for the 350 tbi.

After I finished the work last fall, I did run it some and did compression tests. This is the first time I ran it hard though (skiing). But we only ran it for a little while because of the oil leak. The smoke seemed to be lessening. Hopefully it will go away after running it more.

So, no shot at squeezing more RTV or some other sealant in that gap to plug the leak then? New gaskets for the intake manifold when I remove and put back on?

ahhudgins

05-07-2011, 10:49 AM

I agree with mcantamessa, you need more sealer. I stopped using the front and rear gaskets on the Fords I've done because they like to shift and slip when you tighten them down. If you want to use the gaskets, put the sealer on both sides and let it get tacky before assembly. Do it right and remove the intake and get new gaskets. You'll be glad you took the extra time.

oldairboater

05-07-2011, 10:51 AM

Squeezing extra sealant into that gap most likely will not work but you can try it. Sealant works best by being compressed between surfaces.

JimN

05-07-2011, 10:53 AM

Thanks for the help. As far as being mechanically inclined, I don't have experience with engines but I'm willing to read up and give things a go. I Learned a lot last year doing the head gasket replacement.

I did use marine gaskets (skidim) and followed the shop manual for the torque specs etc. I also did re-use the head bolts. Maybe it was a bad idea but the manual said it was ok for my engine. Some of the engines use bolts that stretch but not for the 350 tbi.

After I finished the work last fall, I did run it some and did compression tests. This is the first time I ran it hard though (skiing). But we only ran it for a little while because of the oil leak. The smoke seemed to be lessening. Hopefully it will go away after running it more.

So, no shot at squeezing more RTV or some other sealant in that gap to plug the leak then? New gaskets for the intake manifold when I remove and put back on?

You don't want to re-use gaskets, even if they weren't used for long. If you look at the new ones, there's a bead of sealant that's activated with heat.

Technically, all bolts/metals stretch when in tension but it's a matter of how much and how close to the yield point it gets. Once at the yield point, they must be replaced because they'll never return to the original dimension and the hardness changes.

As long as the engine isn't extremely high compression, reusing them once is OK but I would replace them if it's torn down again. They're not so expensive that a new set will break the bank but a new set could mean the reliability will be restored. The intake bolts are only tightened to about 35 ft/lb, and they aren't under enough tension that reusing will cause any issues.

BIGandUGLY

05-07-2011, 11:12 AM

Great advice in the thread. As bad as i hate to say it you need to remove it and do it again. You arent the first person to do it lol. Like stated above dont be shy when using rtv. Make sure to clean the area of old sealant (rtv) completely and run at least a quarter inch bead across and onto the intake gaskets on either side. Hope this helps.

JLeuck64

05-07-2011, 12:22 PM

If you want to try and reseal that manifold without removing it again it may be possible to add some silicone to the leaking area. Problem with just forcing more into the leaking area is it rarely works its way down in between the parts. Also there is oily residue in between the parts now and that will prevent the new silicone from sticking very well. A few times I have had luck resealing these types of leaks by doing this...
Spray brake clean on the affected area and blow it dry (bone dry!). Have a buddy hold a shop vac on the oil filler spout so it pulls a good strong vacuum on the crankcase. Now you can apply more silicone to the leaking area and do your best to force it into the gap, the extra vacuum will help draw the sealant in between the parts. Have used this technique successfully in the past and it doesn't take as long as removing the intake manifold agains so its worth a shot in my opinion ...

Table Rocker

05-07-2011, 12:35 PM

Your arrow is pointing at the IAC (Idle Air Control) and if you have smoke coming from there, it's possible that you have blow-by.That would also contribute to the oil leak at the intake manifold wouldn't it? I would check the pcv valve (I am assuming there is one on this engine) and make sure it is working well. If you have enough blow by you are going to be chasing oil leaks.

JimN

05-07-2011, 01:06 PM

That would also contribute to the oil leak at the intake manifold wouldn't it? I would check the pcv valve (I am assuming there is one on this engine) and make sure it is working well. If you have enough blow by you are going to be chasing oil leaks.

Not necessarily. Blow by can be only a ring/cylinder issue.

wtrskr

05-07-2011, 01:33 PM

I did have some smoke coming out of the hose attached to the PCV valve if that makes any difference. I didn't notice any of the smoke until I lifted the engine cover to check everything. It wasn't terrible amounts of smoke but didn't seem normal either.

I realize I didn't respond about the battery. It was barely turning over then nothing after a little while. I was convinced the battery or alternator was just a separate issue. Just a couple of minutes ago I went out to the garage and it started up without recharging the battery. Maybe it just needed to sit?

While we are on the topic of my engine, a separate but possibly related question. I didn't mess with the timing after doing my head gasket replacement last fall. I tried just replacing the distributor in the same spot and didn't turn over the engine. Should I deal with the timing? Does the computer calibrate the timing on its own on a '94? The engine seemed to be running fine minus the oil leak and smoke.

Thanks.

Table Rocker

05-07-2011, 02:24 PM

Not necessarily. Blow by can be only a ring/cylinder issue.Yes, but I mean the pressure blowing past the rings can cause higher pressure in the crankcase and oil leaks in places you wouldn't normally see them. With enough blow by, the pcv gets pretty nasty and doesn't do it's job as well as it should.

wtrskr

05-07-2011, 05:18 PM

I don't know what to do as my next step now. It doesn't appear that the battery was the reason I couldn't start the engine. Today I ran my blower for a couple of minutes, flipped on lights, etc., so the battery is fine. I also started, and immediately shut off, the boat twice today.

Last night, out at the lake, we waited at least ten minutes (in between rowing with skis) before trying to fire it up without luck. So why wouldn't it start hot last night but did cold today?

I'm less worried about the oil leak because I know I can take off and replace the manifold if that is what needs to be done.

I tested compression before and after the head gasket replacement. One cylinder was a little low but within the shop manual's tolerance (at least 75% of the highest). I think that was a valve issue and I can explain why i think that if it is important.

So what else can I test? Or, should I just go out, use it, and see what happens?

1redTA

05-07-2011, 06:19 PM

on the front and back of the valley a 3/8 bead is good to use and I like to extend the bead up the sides of the intake a good 3/4".
Make sure you don't slide the manifold around set it straight down then start all the intake bolts by hand and follow the tightening sequence using steps to achieve the final torque no.

JimN

05-07-2011, 07:30 PM

I did have some smoke coming out of the hose attached to the PCV valve if that makes any difference. I didn't notice any of the smoke until I lifted the engine cover to check everything. It wasn't terrible amounts of smoke but didn't seem normal either.

I realize I didn't respond about the battery. It was barely turning over then nothing after a little while. I was convinced the battery or alternator was just a separate issue. Just a couple of minutes ago I went out to the garage and it started up without recharging the battery. Maybe it just needed to sit?

While we are on the topic of my engine, a separate but possibly related question. I didn't mess with the timing after doing my head gasket replacement last fall. I tried just replacing the distributor in the same spot and didn't turn over the engine. Should I deal with the timing? Does the computer calibrate the timing on its own on a '94? The engine seemed to be running fine minus the oil leak and smoke.

Thanks.

You absolutely should check the timing. The ECM works with the timing as needed, based on the advance table in the program and any knock information coming from the knock sensor but it doesn't know where base timing is, which could be why it didn't want to crank. If the engine is hot and the timing is advanced too far, it's hard to crank against the compression.

If you have a code reader that has a switch for putting the ECM in diagnostic mode, use it and start the engine. If you see the timing mark jumping around, it doesn't have this function and in this case, shut it down and look for the ALDL connector at the rear of the engine. Remove the cover and look for two terminals marked A and B. Bend a paper clip into a 'U' shape and insert it into terminals A & B. Start teh engine and look for the timing mark, setting it to 10°BTDC. Tighten the hold-down and verify that it's still at 10°. Remove the paper clip and snap the cover back in place. If it was advanced much more than 10°, it may have run like a dog because the total advance would have been sufficient to cause knock and the ECM's response to knock is to pull the timing back in 5° increments until the knock goes away.

wtrskr

05-09-2011, 12:03 AM

Ok, I've done some research about timing and I'm not sure if I understand this correctly. I didn't set the timing following the head gasket replacement last fall partly because I couldn't figure out how to turn the engine over by hand.

If I have a timing light, do I understand correctly that I don't need to worry about turning over the engine by hand to TDC? I just start the engine, the timing light tells me what the current timing is set to, then I adjust the distributor from there? Two person job I assume? One for timing light, one to ajdust distributor?

Prior to this, I figured they way I'd have to set the timing would be by turning the engine over by hand until the appropriate tick on the harmonic balance lined up. Then I'd do something with the distributor after that, all with the engine off.

JimN

05-09-2011, 03:35 AM

Ok, I've done some research about timing and I'm not sure if I understand this correctly. I didn't set the timing following the head gasket replacement last fall partly because I couldn't figure out how to turn the engine over by hand.

If I have a timing light, do I understand correctly that I don't need to worry about turning over the engine by hand to TDC? I just start the engine, the timing light tells me what the current timing is set to, then I adjust the distributor from there? Two person job I assume? One for timing light, one to ajdust distributor?

Prior to this, I figured they way I'd have to set the timing would be by turning the engine over by hand until the appropriate tick on the harmonic balance lined up. Then I'd do something with the distributor after that, all with the engine off.

If you already had it running, don't worry about manually getting it to TDC. If it was way off, it would either not run at all or you'd hear things that would make you want to shut it down. If you release the gas struts for the engine cover so it lays back all the way (be careful to avoid letting it fall back- that could make the screws pull out from the floor), you'll have easier access to the distributor. Loosen the hold-down bolt just enough to let you turn it but not so loose that it's really easy. Start it with the paper clip in place and use an open end wrench to turn the distributor- you won't like it if you grab it from the top with your hand on the spark plug wires- trust me. Once you get it to 10°BTDC, snug the hold down bolt and make sure it didn't creep. Remove the paper clip and if you check the timing, you'll see that the timing mark jumps around- this is normal and is called 'spark stabilization'.

If you have the kind of timing light that allows you to adjust the light to different degrees of advance, you can check just how far off the timing is. Since it cranks hard when it's warm, I'd guess that your base timing is at about 20-25° now and this won't happen once you set it to 10°.

If you ever need to turn it over by hand, remove the spark plugs, remove the raw water pump and put a wrench on the bolt that holds the crank pulley in place. It will be easier to turn it over and the bolt is tight enough that it won't back out.

wtrskr

05-13-2011, 09:55 AM

I picked up a timing light but couldn't get it started to do the adjustment.

After having no luck I decided to crank the engine until the line on the harmonic balancer was close to Top Dead Center. Then I went to the distributor and tried lining it up so that the rotor was facing #1. It still woudln't start. I tried moving a little bit in both directions too.

I don't think any gas was coming out of the injectors. I could her the fuel pump and it was just replaced last year. Any reason why gas wouldn't be coming out?

JimN

05-13-2011, 11:37 AM

please delete this post.

JimN

05-13-2011, 11:43 AM

I picked up a timing light but couldn't get it started to do the adjustment.

After having no luck I decided to crank the engine until the line on the harmonic balancer was close to Top Dead Center. Then I went to the distributor and tried lining it up so that the rotor was facing #1. It still wouldn't start. I tried moving a little bit in both directions too.

I don't think any gas was coming out of the injectors. I could her the fuel pump and it was just replaced last year. Any reason why gas wouldn't be coming out?

Does the timing light have a dial on it with degree settings? Use that to determine where the distributor is. Start high, like 20°- 30° and work backward from there- if you see the light flash far from the timing mark, I would advise that you manually find TDC by looking at when the valves open and close. Remember- for every one distributor rotor revolution, the crankshaft rotates twice and it's possible to be off by 180°.

If you removed the plug wires from the cap, it's possible that you're 60° off, or more. Since it's possible that you don't have enough slack to rotate the distributor +/- 60°, you can use the dial on the timing light to find TDC and shift the wires one position to get it where it needs to be. I would recommend marking the cap with the plug number and do the same on the wires, at each end.

You'll have to check the fuel pressure to be sure that you have fuel.

wtrskr

05-13-2011, 12:31 PM

I know I'm learning because I actually followed that.

I picked up the cheap timing light with just the one button on it. No timing adjustments.

I did look in the spark plug hole to make sure that the #1 piston was on the upstroke. Then I followed the plug cord to the distributor, removed the distributor cap, and checked that the rotor roughly lined up with #1. I doubt I was exact because the line on the harmonic balancer wasn't exactly at 0 degs and I don't know how to exactly match the rotor with the dist. It should have been pretty close though.

I just started it in the garage a couple of days ago. I'll try it again this eve.

JimN

05-13-2011, 04:20 PM

I know I'm learning because I actually followed that.

I picked up the cheap timing light with just the one button on it. No timing adjustments.

I did look in the spark plug hole to make sure that the #1 piston was on the upstroke. Then I followed the plug cord to the distributor, removed the distributor cap, and checked that the rotor roughly lined up with #1. I doubt I was exact because the line on the harmonic balancer wasn't exactly at 0 degs and I don't know how to exactly match the rotor with the dist. It should have been pretty close though.

I just started it in the garage a couple of days ago. I'll try it again this eve.

As I posted, the crank rotates twice for every rotation of the distributor. Does it backfire at all? If it's 180° off, it should wake the dead.

Put the timing light clamp on the coil wire- if that's not well seated or is faulty, you'll never get it started.

Also, if you're cranking for a long time, make sure the fuel system fuel is pulled to avoid flooding the motor, which has already happened. Pull all of the plugs and put rags or paper towels in front of the plug holes to catch the fuel spray, then crank it for a few seconds. Remember- the plugs don't need to be in place to set the timing. If it had a carb, I would tell you to set the timing with all of the plugs out so there's no vacuum but with injectors, the fuel is still delivered and that's why I would stop the fuel pump/injectors.

Smell your oil, too. If it smells strongly of gasoline, do an oil change- the gas will dilute the oil and cause wear.

wtrskr

05-13-2011, 05:28 PM

That is very helpful (like all your posts). It didn't hit me that I could use the timing light without getting the engine running until that post.

My last post was meant to describe why I don't think I'm off by 180 deg. The #1 piston was at the top and the rotor was at the spot to fire #1. If I was off by 180 wouldn't the piston have been down when the rotor hit #1 (sorry if my terminology is bad)?

I'll pull all the plugs, pull the fuel pump fuse, and turn it over to get any gas out of the cylinders.

I've never used this timing light thingy. If I put the clamp on the coil, am I assuming correctly that I just look for the light to flash to make sure the coil is sending volts to the distributor?

The timing light cords don't reach my battery. There is no reason why I couldn't pull up my car and use the car battery to power the timing light, right?

JLeuck64

05-13-2011, 05:41 PM

Just clip the timing light positive lead to the heavy cable on the starter solenoid. It is connected directly to the battery and just may be closer to than your battery ( ; black lead can go on any good ground connection.

For what its worth... I have seen a few timing lights that have an inductive lead (lead that goes around the plug wire) that is polarity sensitive. In other words it wont work unless it is pointing the correct direction on the plug wire.

JimN

05-13-2011, 09:19 PM

That is very helpful (like all your posts). It didn't hit me that I could use the timing light without getting the engine running until that post.

My last post was meant to describe why I don't think I'm off by 180 deg. The #1 piston was at the top and the rotor was at the spot to fire #1. If I was off by 180 wouldn't the piston have been down when the rotor hit #1 (sorry if my terminology is bad)?

I'll pull all the plugs, pull the fuel pump fuse, and turn it over to get any gas out of the cylinders.

I've never used this timing light thingy. If I put the clamp on the coil, am I assuming correctly that I just look for the light to flash to make sure the coil is sending volts to the distributor?

The timing light cords don't reach my battery. There is no reason why I couldn't pull up my car and use the car battery to power the timing light, right?

Re-read my comments about the rotation of the crank vs the distributor. The distributor only rotates 180° when the crank rotates 360°. Each cylinder goes through all four strokes before the rotor returns to the beginning of the firing order and that means it's possible that the piston can be at the top of the stroke but it may be the wrong part of the cycle. This is why I mentioned looking at the valves to see when the intake valve has closed. The spark occurs before TDC, but it won't work if it happens when there's no fuel in the cylinders- if the rotor is 180° off, the intake valve should be opening, but the exhaust valve opens. When the compression phase occurs, it happens when the piston should be pushing exhaust out and when the spark occurs, there's no fuel in the cylinder because it just pulled air in through the exhaust valve.

JimN

05-13-2011, 09:22 PM

If anyone wants to have more filtering capacity on a 5.0 L/5.7 L engine, the AC PF-1218 is a larger filter with the same base. Some boats will have a clearance problem because of the size, though.

wtrskr

05-14-2011, 12:26 AM

.... Each cylinder goes through all four strokes before the rotor returns to the beginning of the firing order and that means it's possible that the piston can be at the top of the stroke but it may be the wrong part of the cycle. .......

I feel kinda embarrassed about that one. I knew that. I was thinking about it wrong. For some reason I was thinking one rotation of the crankshaft pushed the piston up and one rotation down.

wtrskr

05-14-2011, 12:41 AM

I got it started right away this evening after first using the timing light (without the fuel pump fuse) to see if the timing was close.

As I cranked, with the fuel pump now in, I could see the injectors squirting gas right away which I couldn't see during my later tries a couple of days ago. It was pretty hard to see exactly what the timing was when the engine was rotating slowly with the fuse out, but I could tell I was in the ballpark. After starting the engine, I could easily see that it was running at well more than 10 degs before top dead center. It probably was something different before I started screwing with the distributor the last couple of days.

I put the paper clip ends in A and B and the RPMs slowed down a little. I got it to 10 degs, or very close to that, and then pulled the paper clip. The RPMs kicked up pretty darn fast (didn't check the actual) after the paper clip came out. I was running out of water in my bucket so I shut it down shortly after. Why does the engine speed up after pulling the clip? Did I properly reset it, or was I supposed to leave it running at high RPMs longer to let the computer do its thing?

wtrskr

05-14-2011, 12:51 AM

If you want to try and reseal that manifold without removing it again it may be possible to add some silicone to the leaking area. Problem with just forcing more into the leaking area is it rarely works its way down in between the parts. Also there is oily residue in between the parts now and that will prevent the new silicone from sticking very well. A few times I have had luck resealing these types of leaks by doing this...
Spray brake clean on the affected area and blow it dry (bone dry!). Have a buddy hold a shop vac on the oil filler spout so it pulls a good strong vacuum on the crankcase. Now you can apply more silicone to the leaking area and do your best to force it into the gap, the extra vacuum will help draw the sealant in between the parts. Have used this technique successfully in the past and it doesn't take as long as removing the intake manifold agains so its worth a shot in my opinion ...

I did try this trick to plug the manifold leak. I'm not sure if the vacuum did anything or not. I forced quite a bit of high temp RTV in the space between the manifold and block, and all around the area.

When I look at it now, I can't help but think "how the heck is oil going to find its way through there". It may not work long term but at the very least it buys me time to make sure everything else is in order before worrying about removing and reinstalling the intake manifold.

wtrskr

05-21-2011, 03:39 PM

This is not good.

I still have a serious oil leak and not in the spot that I thought. I believe the leak caused me to run dry of oil. I had an overheat and I'm not sure if it caused damage.

I took it for a spin today. As I drove, I consciously glanced over at the engine temp to make sure it was in a normal range. I also lifted the engine cover multiple times to make sure my RTV patch job wasn't leaking oil.

In a very short period of time, the temp went from 140 ish, to off-the-charts hot. At first I was convinced it was an error in the gauge but I shut down the engine anyway. I inspected things more closely and found lots of oil under the engine especially on the drivers side near the back of the engine.

No water in oil. No water on spark plugs. The engine didn't really smoke much. I could only tell it was hot because of the temp gauge. Impeller was fine.

Thoughts? Damage from the heat/low oil done already even though I shut it off right away? Where could oil be leaking that quickly from? Cracked block?

JLeuck64

05-21-2011, 03:52 PM

Valve cover gasket could easily cause the leak you are describing.

Intake manifold leak would be more apparent after the engine is shut down.

JimN

05-21-2011, 04:44 PM

This is not good.

I still have a serious oil leak and not in the spot that I thought. I believe the leak caused me to run dry of oil. I had an overheat and I'm not sure if it caused damage.

I took it for a spin today. As I drove, I consciously glanced over at the engine temp to make sure it was in a normal range. I also lifted the engine cover multiple times to make sure my RTV patch job wasn't leaking oil.

In a very short period of time, the temp went from 140 ish, to off-the-charts hot. At first I was convinced it was an error in the gauge but I shut down the engine anyway. I inspected things more closely and found lots of oil under the engine especially on the drivers side near the back of the engine.

No water in oil. No water on spark plugs. The engine didn't really smoke much. I could only tell it was hot because of the temp gauge. Impeller was fine.

Thoughts? Damage from the heat/low oil done already even though I shut it off right away? Where could oil be leaking that quickly from? Cracked block?

A better question is "Where is the oil going?" If it's not in the bilge, it has to be burning off and you should see a whole lot of James Bond smoke screen or at least a heavy oil sheen behind you. How often do you check the oil level?

Re: the RPM increase after removing the paper clip- putting it in diagnostic mode (that's what the paper clip is for- it disables spark stabilization so you can see the timing mark in one place) requires that the engine speed be increased to 1000RPM. If you don't manually raise it, it drops and sometimes won't even idle well because it's too low- the ECM doesn't operate the IAC the same as when it's not in diagnostic mode and if you were using a Tech I or something like that, it would tell the IAC to open enough to go directly to 1000RPM, which is the correct speed for setting the timing. It's probably not too far off but I would check it later at that speed.

How much damage was done depends on how long and how hard you ran it without oil, if that's what really happened. Did you refill it after it cooled down? How much oil was needed to bring it back up to normal "full" level?

Look inside of the valve covers for anything that doesn't seem normal, like tan/brown foam.

How well did it run?

In a previous post, I wrote "Also, if you're cranking for a long time, make sure the fuel system fuel is pulled to avoid flooding the motor, which has already happened." and "Smell your oil, too. If it smells strongly of gasoline, do an oil change- the gas will dilute the oil and cause wear."

wtrskr

05-21-2011, 05:19 PM

When I first saw the oil leak I actually thought it might be the valve cover but a friend, who was also in the boat, convinced me otherwise. I figured oil may have found its way along the manifold/block crease to the distributor area, thus making it appear that the rear of the intake of the manifold was the location.

It is hard to tell the location because I think oil was dripping down and was flung around as the engine spun.

I checked the oil after last time out and it was in the correct range. It was maybe a little on the low side but not much. This is only the 2nd time running (at least on the lake) it since I changed the oil last fall.

I did redo the timing at 1000 RPMs a few days ago. After pulling the paperclip the engine jumped to aprox. 2200 RPMs before slowing back down. I assume that is just the computer doing its normal calibration.

I have to pick up more oil and see how much I have to replace. I'll also check inside the Valve cover for foam.

I think it ran just fine. I don't think it is firing up quite as easily as it had prior to the work I had done, but besides that, everything seems good. I drove around at 36 mph as if I were pulling a skier, then stopped, checked things, and repeated.

Regarding that last comment... I did check the smell of the oil and it seemed fine. I hadn't cranked it a ridiculous amount, nor did I give it any throttle when I was cranking. I took off the flame arrestor and the injectors didn't appear to be spraying gas on those last few tries, so I don't think I had much gas in the oil.

As before, I did notice small amounts of smoke coming from the IAC and from the tube that attaches to the flame arrestor (PC valve?). It seemed like less smoke than before.

JimN

05-21-2011, 05:41 PM

Opening the throttle doesn't do the same thing as a carb- your throttle isn't directly connected to an accelerator pump and it won't squirt more gas in, so you may be OK WRT gas in the oil.

Re: oil slinging around when it runs- it still has to go somewhere and if 5 qts went onto the flywheel, it would have drained out of the bell housing, into the bilge. If you don't have much/any oil in the bilge, it must have burned off, either as blow-by or directly out of the exhaust. You would never see smoke coming out of the IAC opening while it's running- that would be impossible. If you saw oil smoke coming out after it was shut down, I would have to say that you're leaking into the intake manifold and it's being diluted by the gas to the extent that it doesn't kill the motor but it still leaves the engine. In this case, you should also see oil smoke coming out of the throttle body, if you were to open the throttle. If it only comes out of one hole, that will tell you which side is leaking because the intake manifold has a septum that divides the two cylinder banks.

I wouldn't recommend running it again until you pull the intake and make sure it's not bypassing the gasket. Did you use any sealant on the intake gasket? You don't want to use any except at the ends, not where the intake mates with the heads.

wtrskr

05-21-2011, 08:33 PM

Checked the dipstick now that the boat has sat. I do still have quite a bit of oil. The dipstick looked dry at the time but that is probably normal after running it. The oil in the bilge, the overheat, and the dry looking dipstick led me to beleive that I had run out of oil.

What else could have caused the temp to jump like that? Everytime I peeked at the guage it was 140, 140, 140, 140.....then all the way to the right (240).

A lot of the oil was sitting right below the back outer edge of the valve cover on the metal ledge right next to the carpet. I would not be at all suprised if that is the only place the oil was leaking from.

I did not use RTV on the gaskets. I did use some Permatex Form-a-gasket with the gaskets, although I don't think I did for the intake manifolds. If I did, it was a very small amount.

I couldn't find anywhere whether or not to use that stuff. Clymer's manual did call for gasket maker but that may have been written a while ago with older gasket technology. Since then, I beleive I saw that it isn't needed anymore.

JimN

05-21-2011, 09:30 PM

Checked the dipstick now that the boat has sat. I do still have quite a bit of oil. The dipstick looked dry at the time but that is probably normal after running it. The oil in the bilge, the overheat, and the dry looking dipstick led me to beleive that I had run out of oil.

What else could have caused the temp to jump like that? Everytime I peeked at the guage it was 140, 140, 140, 140.....then all the way to the right (240).

A lot of the oil was sitting right below the back outer edge of the valve cover on the metal ledge right next to the carpet. I would not be at all suprised if that is the only place the oil was leaking from.

I did not use RTV on the gaskets. I did use some Permatex Form-a-gasket with the gaskets, although I don't think I did for the intake manifolds. If I did, it was a very small amount.

I couldn't find anywhere whether or not to use that stuff. Clymer's manual did call for gasket maker but that may have been written a while ago with older gasket technology. Since then, I beleive I saw that it isn't needed anymore.

Did you check your oil cooler yet? I'd bet it's clogged.

wtrskr

05-22-2011, 12:02 PM

Just took a look. Trans cooler doesn't have any obstructions that I can see.

JimN

05-22-2011, 12:22 PM

Just took a look. Trans cooler doesn't have any obstructions that I can see.

Was it on the trailer, or in the water when you checked the oil cooler? Did you look at the hull fitting for the raw water? That could be clogged. You said the impeller was good- was that before the overheat, or after? If the raw water supply was flowing freely, the temperature shouldn't have shot up so fast, so I suspect some kind of problem with water supply, or possibly the thermostat couldn't open.

wtrskr

05-22-2011, 03:31 PM

I didn't yet check the hull fitting.

I checked the impeller after the overheat. Right after the overheat I put my hand over the impeller cover and it was cool. I have since pulled the impeller all the way out to inspect. Water drained from that area when I took the cover off, so water seemed to at least getting to that location.

I checked the trans cooler on the trailer in my garage.

Is it possible that the guage or the sensor was just out of whack?

wtrskr

05-22-2011, 04:37 PM

Hull fitting looks fine too.

Should my next step be to test or replace the thermastat?

JimN

05-22-2011, 04:39 PM

I didn't yet check the hull fitting.

I checked the impeller after the overheat. Right after the overheat I put my hand over the impeller cover and it was cool. I have since pulled the impeller all the way out to inspect. Water drained from that area when I took the cover off, so water seemed to at least getting to that location.

I checked the trans cooler on the trailer in my garage.

Is it possible that the guage or the sensor was just out of whack?

It's possible but I would also check the wiring to the sensor. If it overheated badly, you would have smelled something different when you opened the engine cover and would have felt heat radiating from the engine/exhaust manifolds. Squeeze the exhaust tubes- i they're not firm and collapse fairly easily, look into the exhaust flappers and check for small blisters on the plastic fitting that mounts to the transom.

Do you have an infra-red thermometer? Use that to verify the temperature gauge next time you run it. You can shoot at the intake manifold, right next to the sensor. If you see extremely different temperatures from what the gauge shows, I would remove the sender and test its resistance in hot water.

wtrskr

05-22-2011, 10:11 PM

I did not notice any overheat symtoms, just the guage showing hot.

Here's my plan. I removed the valve cover so I will carefully put that back in place after degreasing the surfaces. The rubber gasket may have slipped out of place or maybe I didn't get it correctly situated before tightening it. Hopefully that will take care of the oil leak. I think I will also replace the thermostat in case that was the issue in regards to the engine heat. Then I'll just watch the temp real closely and see how it goes.

wtrskr

05-24-2011, 12:08 AM

I went to pull the little green plastic cover so I could see the connection to the temp sensor and the whole thing popped right off.

If I just put it back in place, does anybody know if it will it be a good enough connection to still reliably send the temps? Or, should I try doing something to connect it better?

I didn't have the battery connected to see what happend to the guage.

JimN

05-24-2011, 08:10 AM

I went to pull the little green plastic cover so I could see the connection to the temp sensor and the whole thing popped right off.

If I just put it back in place, does anybody know if it will it be a good enough connection to still reliably send the temps? Or, should I try doing something to connect it better?

I didn't have the battery connected to see what happened to the guage.

You should be OK- that's just the terminal on the wire. If you have a multi-meter, measure the resistance from the pin to the base when it's cold and start the engine. Measure it immediately after starting and watch the gauge (you can slide the wire on part way and leave enough room to touch the probe to the pin), measuring the resistance about every minute, or so. If the gauge shoots up to hot, measure the resistance and if it doesn't feel like the engine is radiating a lot of heat when it shows hot, wiggle the wire to the sensor, working back to the harness. If the gauge goes back to normal, look for a short in the wire or melted wire loom.

Also, while it's running, touch the exhaust riser and notice if one side is hotter than the other. If one is a lot hotter than the other, make sure all of the raw water hose clamps are tight on the inlet side, working from the hull fitting to the pump. If they're tight, re-check the impeller- if the vanes are soft or if the impeller is more than a year old and was left in the pump over the winter, replace it. It can look fine but if the vanes are too soft, they won't draw enough water in at high speeds.

wtrskr

05-25-2011, 10:10 AM

What does the sensor in my picture do? I ask because pulled it off after starting the engine in my driveway and the temp guage slowly went up as normal without it attached. What senses the engine temps if not that?

I happen to have access to a multimeter but I don't know how to use one. Maybe I'll try figuring it out.

- felt risers and they both warmed up at the same rate, impeller was sucking water out of bucket as normal and water coming out of both exhaust flaps.

- couldn't find an oil leak anywhere so either re-attaching the valve cover fixed that problem, or the oil only leaks at higher RPMs. A question about that, if it were my head gasket leaking would it be normal for it to only leak at high rpms?

- Afterwords tested thermometer in water on the stove and it is working fine.

I guess my next step will be to run it harder on the water again to see what happens

JimN

05-25-2011, 10:51 AM

What does the sensor in my picture do? I ask because pulled it off after starting the engine in my driveway and the temp guage slowly went up as normal without it attached. What senses the engine temps if not that?

I happen to have access to a multimeter but I don't know how to use one. Maybe I'll try figuring it out.

- felt risers and they both warmed up at the same rate, impeller was sucking water out of bucket as normal and water coming out of both exhaust flaps.

- couldn't find an oil leak anywhere so either re-attaching the valve cover fixed that problem, or the oil only leaks at higher RPMs. A question about that, if it were my head gasket leaking would it be normal for it to only leak at high rpms?

- Afterwords tested thermometer in water on the stove and it is working fine.

I guess my next step will be to run it harder on the water again to see what happens

What color is the wire that you disconnected from that sensor? Your engine should have one sensor that connects to the gauge and another that connects to the ECM but I'll have to check my manual to be sure about your boat (it's a '94, right?).

Did you see oil around the 4 valve cover hold-down bolts? Sometimes, the seal shrinks and needs to be replaced because it can compress over time. This could be why you had a leak. It's an O-ring, and shouldn't be expensive. DO NOT CRANK ON THE HOLD-DOWN BOLTS!!!! They're very hard (break easily) and a PITA to remove if one snaps off.

wtrskr

05-25-2011, 11:51 AM

Yep a '94.

I beleive it is a white wire that goes to that sensor. I also think it has a black pinstripe on it. If there are two sensors it would make sense that this is the one that goes to the ECM.

I didn't find any oil on the top of the valve cover so I don't think the valve cover hold down bolts are the problem. I didn't torque them down too tight either because the valve cover gasket is rubber. I didn't think it would need to be down that tight for the rubber to stop any leaks.

The valve cover was difficult to get situated because that dang dipstick that squeezes between between the valve cover and the exhaust manifold. The dipstick is pinched but I had to un-pinch it with a pliers because I had to go through the dipstick to change the oil last fall.

If I still find leaking at higher RPMs I think I will have to take off the engine cover at a lake and see if I can pinpoint the location.

wtrskr

05-31-2011, 01:34 PM

I think I'm in good shape now.

-Pulled 4 skiers this weekend with no overheating issues. I'm not sure why the guage shot to 240+ last time out. I'll just keep an eye on it going forward.

-After re installing the valve cover I almost completely eliminated the oil leak. JimN, you were right, I am getting a small leak where the valve cover hold down bolts go through the valve cover. I'll get some o-rings to take care of that.

-No more smoke is coming out of the throttle body area.

-It still isn't starting real well. I haven't had the battery tested but will do so now. Correcting the timing helped, but it still isn't turning over very fast. Hopefully I'll just need a new battery and I'll be good to go.

Thanks for all the help.

wtrskr

06-01-2011, 02:59 PM

I guess I'll keep this thread going.

I went to remove the battery so I could have it tested and I discovered the rubber red positive terminal cover was melted.

Any ideas as to a cause?

JimN

06-01-2011, 03:52 PM

I guess I'll keep this thread going.

I went to remove the battery so I could have it tested and I discovered the rubber red positive terminal cover was melted.

Any ideas as to a cause?

Long crank times will do that, especially if the battery was weak. When the voltage drops, current must increase in order for the starter to do its job as well as it does with a normal battery voltage (P=I x E) and when more current flows, the connections, cables and devices being used get hotter. This also happens frequently when the battery terminals aren't tight and/or clean enough. They may look clean, but as soon as the lead has a dull gray coating, it's not. Excessive heat is also a killer of starters and can cause slow cranking later. If an engine doesn't fire up after a few seconds of cranking, it has a problem, especially if it's injected. It's best to stop and find out why instead of cranking until the battery dies.

wtrskr

06-01-2011, 04:32 PM

Thanks. I'll continue with my plan to check the battery and the starter.

wtrskr

06-08-2011, 10:18 PM

For closure: The battery and starter checked out fine. Cleaned and reconnected both battery and starter. It starts much better now.

A separate question. The dash has an engine hot light and a transmission hot light. Is one of those supposed to flash the MEFI error codes when I put it into diagnostic mode with a paperclip?

I ask because I've seen other posts about the error codes flashing on the check engine light. I didn't have any flashes on my dash when I put the boat into diagnostic mode to set the base timing.

Thanks.

wtrskr

06-12-2011, 11:25 PM

Just to be sure I'm getting my boat running the way it should I read the diagnostic codes. It flashed 33 which is MAP sensor voltage above or below preset limit. I cleared the code, ran the boat this weekend, and when I checked the codes after, it again flashed 33.

I have have the Clymer manual (at least for the time being). Before replacing the MAP, it says to check for a shorted circuit in the wiring to the ECU. Any suggestions on how to test the connections? I've never used a multimeter but I have easy access to a relative's.

I am not even sure if I've correctly identified the MAP sensor. I can attach a picture of what I think it is. I believe it is attached to the ECU with the vacuum hose going from it, around the flame arrestor, to the throttle body.

I'll do more research on my own. Any tips are appreciated though.

JimN

06-13-2011, 08:17 AM

Just to be sure I'm getting my boat running the way it should I read the diagnostic codes. It flashed 33 which is MAP sensor voltage above or below preset limit. I cleared the code, ran the boat this weekend, and when I checked the codes after, it again flashed 33.

I have have the Clymer manual (at least for the time being). Before replacing the MAP, it says to check for a shorted circuit in the wiring to the ECU. Any suggestions on how to test the connections? I've never used a multimeter but I have easy access to a relative's.

I am not even sure if I've correctly identified the MAP sensor. I can attach a picture of what I think it is. I believe it is attached to the ECU with the vacuum hose going from it, around the flame arrestor, to the throttle body.

I'll do more research on my own. Any tips are appreciated though.

Unplug the hose from the MAP sensor and let it hang down- if liquid comes out, remove it from the throttle body and use compressed air to clear it out. Try it again if it's not a PITA.

The best way to test a MAP sensor involves using a multi-meter and a vacuum pump to make sure the sensor is operating properly. You could also call a parts store and find out if they have a way to test it. If there's no major evidence that it overheated badly, I doubt the wiring is bad.

wtrskr

06-25-2011, 09:55 AM

I replaced the Map sensor and it is still storing code 33. What else should I check for? Vacuum test? Might the thread have come full circle to my first post with the culprit being issues related to the intake manifold not being properly sealed.

The boat bogs a little when I first put it in gear. Not bad though.

I did also encounter another episode of the guage shooting to 240. I have a new impeller so I will replace the current one in case it just isn't able to keep up because it is getting older. That seems strange though because I ran it harder recently with no overheat. No engine alarm went off and no light on the dash. The exhaust manifolds were not too hot too touch. No steam or smoke was evident.

I can do a Engine Temperature Sensor test. I don't know if that is worthwhile though because the guage reads fine most of the time. Therefore, I'm sure the test will show that the sensor is fine.

Could code 33 and an overheat be related somehow?

If an indmar dealer hooked it up to their computer would it kick out more detailed information to isolate my problems?

JimN

06-25-2011, 10:31 AM

I replaced the Map sensor and it is still storing code 33. What else should I check for? Vacuum test? Might the thread have come full circle to my first post with the culprit being issues related to the intake manifold not being properly sealed.

The boat bogs a little when I first put it in gear. Not bad though.

I did also encounter another episode of the guage shooting to 240. I have a new impeller so I will replace the current one in case it just isn't able to keep up because it is getting older. That seems strange though because I ran it harder recently with no overheat. No engine alarm went off and no light on the dash. The exhaust manifolds were not too hot too touch. No steam or smoke was evident.

I can do a Engine Temperature Sensor test. I don't know if that is worthwhile though because the guage reads fine most of the time. Therefore, I'm sure the test will show that the sensor is fine.

Could code 33 and an overheat be related somehow?

If an indmar dealer hooked it up to their computer would it kick out more detailed information to isolate my problems?

If it overheated badly enough, the intake manifold's seal could be damaged, so it is a possibility. A vacuum leak will show high MAP reading (which indicates low vacuum because of the leak) and yes, connecting it to a diagnostic computer will show this and whether it overheated within 300 key ON/Off cycles.

If you're going to have it connected for diagnostics, it will show the ETC that reports to the computer and that has nothing to do with the gauge.

wtrskr

06-25-2011, 11:17 AM

If the intake manifold isn't sealed it would likely be because I didn't get it sealed right when I did my work last fall. It is tempting to remove and replace the manifold to see if it does the trick but that seems like a lot of work for something that might not be the problem.

Do you see anything wrong with asking a dealer to just run diagnostics and give me their opinion on the problem? I'm not sure if dealers are ok with that, or if they want to to the whole job or nothing? I could also make sure my ECM has the most recent updates while I am at it.

If it is something that is mostly labor such as removing and replacing the intake manifold, I'd probably want to tackle that part myself since I already learned the process.

JimN

06-25-2011, 02:49 PM

If the intake manifold isn't sealed it would likely be because I didn't get it sealed right when I did my work last fall. It is tempting to remove and replace the manifold to see if it does the trick but that seems like a lot of work for something that might not be the problem.

Do you see anything wrong with asking a dealer to just run diagnostics and give me their opinion on the problem? I'm not sure if dealers are ok with that, or if they want to to the whole job or nothing? I could also make sure my ECM has the most recent updates while I am at it.

If it is something that is mostly labor such as removing and replacing the intake manifold, I'd probably want to tackle that part myself since I already learned the process.

When I worked for MC dealers, we would run diagnostics for a fee, usually an hour or two of labor time (requires launch/re-load of the boat and time on the water). We would also document the readings so we would have a copy and could give one to the customer. If a dealer is stupid enough that they require the whole job to be done by them, that's their problem. Labor revenue is labor revenue and it might be a good way to show the less experienced tech(s) how to do this for future cases. There's never a bad time to do some diagnostic training, other than when it's incredibly busy and it might be in the middle of the day but it doesn't take that much time, so...

This needs to be done on the water, not the trailer. Anyone who insists on dong it on the trailer either doesn't know what they're doing or just doesn't want to launch the boat. This test should also include a vacuum test and at least a compression test, preferably with a cylinder leak-down test, too. These three tests will tell you the general health of the motor and if I was doing it, I would start by verifying timing advance. The checksum and program ID will come with the data shown on the screen of the diagnostic computer.

This is less a time for opinions and more for real data and I think I mentioned running diagnostics before- it's not free but the information can save a lot of time hunting for the problem(s), even if it takes three hours at $75/hr, it's worth it.

wtrskr

06-25-2011, 03:32 PM

Great info. I am dropping it off in a little bit. The boat was purchased last year and the only tests have been by me. I'm no trained mechanic, that's for sure. If they put in a legit 3 hours between the launching and all that, and do all test you mention for $75/hour, I'd feel like that is worth it too.

wtrskr

07-07-2011, 01:45 PM

Not done with this one yet. Maybe this should go in the electrical section.

I got a diagnosis from the dealer.

1. The diagnostic computer showed the engine did not overheat. They (and I) think it was a sensor or guage connection issue somehwere.

2. They also found that the Map sensor issue was from the connection. They added a zip tie to hold the connection in place and tested on the computer and it did not throw another code.

Well, I took it out since then and it is again throwing the map sensor code. And Last time out the dash temperature guage bounced up and down. It bounced even more when I wiggled the wire by the sensor (short could be coming from anywhere along that wire though).

I'm thinking to myself that the two issues are likely related. What would be the chances that I have two separate connection/voltage issues?

So my question is, what is my best method to go about trouble shooting the cause. Is there a common connection that provides voltage to the Map Sensor and to the Engine Temperature sensor? If that is the problem, wouldn't it be throwing all my other electrical stuff out of whack too?

Thanks.

JimN

07-07-2011, 03:40 PM

Not done with this one yet. Maybe this should go in the electrical section.

I got a diagnosis from the dealer.

1. The diagnostic computer showed the engine did not overheat. They (and I) think it was a sensor or guage connection issue somehwere.

2. They also found that the Map sensor issue was from the connection. They added a zip tie to hold the connection in place and tested on the computer and it did not throw another code.

Well, I took it out since then and it is again throwing the map sensor code. And Last time out the dash temperature guage bounced up and down. It bounced even more when I wiggled the wire by the sensor (short could be coming from anywhere along that wire though).

I'm thinking to myself that the two issues are likely related. What would be the chances that I have two separate connection/voltage issues?

So my question is, what is my best method to go about trouble shooting the cause. Is there a common connection that provides voltage to the Map Sensor and to the Engine Temperature sensor? If that is the problem, wouldn't it be throwing all my other electrical stuff out of whack too?

Thanks.

Keep wiggling the wires, working away from the MAP sensor- the MAP and ECT share a ground wire on some harnesses. If a zip tie "fixes" the problem, the wires should be checked for resistance/continuity back to the relays and ECM. Also, the loom on the engine's wiring harness should be removed so a complete visual inspection can be performed.

Is this boat one of the ones that had a lot of water in it?

wtrskr

07-07-2011, 04:11 PM

No water issues that I am a aware of. I did replace the head gasket last fall so I had all the wiring peeled back and maybe loosened a connection or something.

I don't really know what I'm doing with the electrical stuff yet and I've been pretty busy lately to dig deeper. To give you an idea where I'm coming from, I had to google what a relay is. I've got the clymers manual at home. Will the wiring diagram in it be helpful? Anything I should look for in the diagram.

It runs pretty well in the meantime so at least it isn't imperative to get it done right away.

wtrskr

07-14-2011, 11:34 PM

I had a little time to inspect things.

The two engine sensor wires (ECM/Guage) share a wiring harness/loom to the back of the engine. At about the halfway point of the wires, the loom was melted and sticking to the intake manifold. I am not sure if it was heat from the wires or the engine that caused the melting? I'm suprised the dealer didn't see it when they did diagnostics. Anyway, the wires at first glance seem to be ok with maybe a little melting of the wire coatings.

I made a quick attempt at using the multimeter with volt readings being my first step. With the engine off, key in the on position, the ECM engine temp sensor was getting about 12V. The guage temperature sensor, the one that had gone wacky on me, was getting about 9V. Does that mean anything? The reading didn't change when I wiggled the wire.

I wrapped the wires in electric tape and went skiing. The temp guage held steady like it was working fine. Still have the map sensor issue though.

I'll be on vacation next week with the boat on a lake, so I'll be able to run it and do any testing that isn't to time consuming to ruin my vacation.

JimN

07-15-2011, 09:55 AM

I had a little time to inspect things.

The two engine sensor wires (ECM/Guage) share a wiring harness/loom to the back of the engine. At about the halfway point of the wires, the loom was melted and sticking to the intake manifold. I am not sure if it was heat from the wires or the engine that caused the melting? I'm suprised the dealer didn't see it when they did diagnostics. Anyway, the wires at first glance seem to be ok with maybe a little melting of the wire coatings.

I made a quick attempt at using the multimeter with volt readings being my first step. With the engine off, key in the on position, the ECM engine temp sensor was getting about 12V. The guage temperature sensor, the one that had gone wacky on me, was getting about 9V. Does that mean anything? The reading didn't change when I wiggled the wire.

I wrapped the wires in electric tape and went skiing. The temp guage held steady like it was working fine. Still have the map sensor issue though.

I'll be on vacation next week with the boat on a lake, so I'll be able to run it and do any testing that isn't to time consuming to ruin my vacation.

The MAP sensor should have 5VDC on the blue wire's terminal, the black wire's terminal is grounded (shared) and the gray wire's terminal will have no voltage when the sensor is disconnected (that one sends the varying voltage to the ECM).

The melted loom is what I was referring to when I posted that a visual inspection should be done. The fact that it melted means it overheated- there's really no other way to cause this, although I have seen boat motors that were overheated repeatedly and they lived a long time.

wtrskr

07-15-2011, 06:35 PM

The MAP sensor should have 5VDC on the blue wire's terminal, the black wire's terminal is grounded (shared) and the gray wire's terminal will have no voltage when the sensor is disconnected (that one sends the varying voltage to the ECM).

The melted loom is what I was referring to when I posted that a visual inspection should be done. The fact that it melted means it overheated- there's really no other way to cause this, although I have seen boat motors that were overheated repeatedly and they lived a long time.

I'll check the Map sensor voltage.

So if it did in fact overheat then the computer should have had that stored. The dealer said that the computer showed no overheat. Is it possible for an overheat to have occured in just a certain area but not where the ECM engine temp sensor is? 1.75 hours of labor and maybe didn't get a computer check showing an overheat and didn't get even a quick visual wire inspection.

I was feeling pretty good that the engine did not overheat until I saw this melting. Last time the guage showed 240, I was able to hold my hands on both exhaust manifolds without burning my hands, no steam or anything that resembled an overheat.

Can there be issues with my motor that are causing an overheat that are unrelated to the cooling system? I ask, because you had suggested a thorough review of the health of the engine. After I replaced the head gasket last fall I did compression tests. I did a vacuum test and that seemed fine as well.

JimN

07-15-2011, 09:05 PM

I'll check the Map sensor voltage.

So if it did in fact overheat then the computer should have had that stored. The dealer said that the computer showed no overheat. Is it possible for an overheat to have occured in just a certain area but not where the ECM engine temp sensor is? 1.75 hours of labor and maybe didn't get a computer check showing an overheat and didn't get even a quick visual wire inspection.

I was feeling pretty good that the engine did not overheat until I saw this melting. Last time the guage showed 240, I was able to hold my hands on both exhaust manifolds without burning my hands, no steam or anything that resembled an overheat.

Can there be issues with my motor that are causing an overheat that are unrelated to the cooling system? I ask, because you had suggested a thorough review of the health of the engine. After I replaced the head gasket last fall I did compression tests. I did a vacuum test and that seemed fine as well.

It's possible to have localized hot areas if the flow of water is blocked by sludge, sand or pieces of an impeller vane. The harness is on top of the intake manifold, so the passage(s) to the intake would need to be blocked but since you had the intake off and didn't see anything in the way, I would have to say that it was the usual type of overheat- bad impeller or clogged raw water cooler. You may have seen areas of paint that looked like they baked off of the intake before you removed it and that's another indication that it got really hot.

The ECM will store overheat for 300 key ON/Off cycles and it really doesn't take long for that many to take place. If the gauge showed 240, I would bet that the wire is still shorting. remove the wire from the sender and see if it goes to zero. If not, the wire is definitely shorted. My guess is that the sender wire is shorted to the ground wire in the loom.

wtrskr

07-16-2011, 12:15 AM

I do have 5V at the map sensor so that is where it should be.

Here is a picture of the melted area. The arrow points to the location on the intake manifold where the wires were stuck to. The paint in that area is chipped off. Most of the rest of the intake manifold has paint on it. That seems to support the localized overheat scenario.

My thought is that the voltage to the guage was being drained becuase the wire was touching the engine metal. Last time out the guage was fine (after wrapping wires in electical tape). However, the time before that, the guage jumped around when I wiggled it and that was before I inspected the wires to find the melted area.

I put in a new impeller. I don't think that was the problem though because the old one seemed fine.

wtrskr

07-16-2011, 12:28 AM

One other point of clarification.

I wouldn't doubt that the engine did overheat prior to my purchasing it, thus maybe the blown head gastket that I discovered shortly after the purchase last summer. This wire melting episode, however, happend more recently. The wire was not melted prior to me removing the intake manifold because I would have seen it.

JimN

07-16-2011, 09:48 AM

One other point of clarification.

I wouldn't doubt that the engine did overheat prior to my purchasing it, thus maybe the blown head gastket that I discovered shortly after the purchase last summer. This wire melting episode, however, happend more recently. The wire was not melted prior to me removing the intake manifold because I would have seen it.

Right- if you don't see melted wore loom, the wires won't be damaged inside of it but there's a possibility that the previous owner had an overheat and replaced the loom to hide it. If the loom looks consistent all over, it probably hasn't been replaced.

If you're still getting the check engine light after making any repair to the wires, try disconnecting the battery cables and letting it sit for a few minutes- the ECM may delete the codes.

wtrskr

07-16-2011, 10:22 AM

The check engine light hasn't come on for me ever. I think mine has a engine temp light and a transmission temp light. I'll try disconnecting the battery to reset the ECM.

I experimented with taking the loom off of the Map sensor wires and started to follow the wire. I stopped where the loom merged into the other looms. It's like a california highway system going from two lanes to 8. Putting the wires back in the loom took more time than I expected.

I have a feeling I'll eventually be removing and reattaching the intake manifold. I hope I didn't drop something in there that is causing blockage. Maybe I dropped a junior mint in there or something.

Thanks for all your help. The boat is headed up North with me now. If it has issues, I won't be the only one in our group with a Mastercraft so skiing won't be ruined.

Thanks for all your help.

JimN

07-16-2011, 10:31 AM

The check engine light hasn't come on for me ever. I think mine has a engine temp light and a transmission temp light. I'll try disconnecting the battery to reset the ECM.

I experimented with taking the loom off of the Map sensor wires and started to follow the wire. I stopped where the loom merged into the other looms. It's like a california highway system going from two lanes to 8. Putting the wires back in the loom took more time than I expected.

I have a feeling I'll eventually be removing and reattaching the intake manifold. I hope I didn't drop something in there that is causing blockage. Maybe I dropped a junior mint in there or something.

Thanks for all your help. The boat is headed up North with me now. If it has issues, I won't be the only one in our group with a Mastercraft so skiing won't be ruined.

Thanks for all your help.

The loom is made on a jig and wrapping it with electrical tape is a lot easier that way. I have had to do the same thing and I agree- it's not a lot of fun.

NOT A JUNIOR MINT, JERRY!

wtrskr

07-23-2011, 11:41 PM

Back from a week at a lake cottage with the boat. I found that disconnecting the Map sensor made it run better so I left it disconnected for most of the week. I am not sure if that was wise but it ran great. No overheats on the guage.

I did find that the intake manifold was getting hot in the area that I mentioned in my previous post. Right after running the engine fairly hard I dipped my hand in the lake then flicked water drops onto that area of the intake manifold, and the water bubbled/boiled.

I am going to post a couple of pictures from my work last fall. I am starting to wonder if the blown head gasket was caused by this specific area getting too hot and not a full out engine overheat.

The first picture is the blown head gasket. This all started when I found water on a spark plug. The top arrow points to the water jacket that I beleive was the culprit behind water getting into the cylinder just to the right of it. The second area points to the general area of the blown gasket.

The second is just a picture of the engine with the head off with an arrow pointed to the water jacket.

So it appears that the head gasket blew in the same area that the intake manifold is now getting hot (starboard side at the mid point). Any ideas why this might be happening or how to deal with it?

JimN

07-24-2011, 10:37 AM

Back from a week at a lake cottage with the boat. I found that disconnecting the Map sensor made it run better so I left it disconnected for most of the week. I am not sure if that was wise but it ran great. No overheats on the guage.

I did find that the intake manifold was getting hot in the area that I mentioned in my previous post. Right after running the engine fairly hard I dipped my hand in the lake then flicked water drops onto that area of the intake manifold, and the water bubbled/boiled.

I am going to post a couple of pictures from my work last fall. I am starting to wonder if the blown head gasket was caused by this specific area getting too hot and not a full out engine overheat.

The first picture is the blown head gasket. This all started when I found water on a spark plug. The top arrow points to the water jacket that I beleive was the culprit behind water getting into the cylinder just to the right of it. The second area points to the general area of the blown gasket.

The second is just a picture of the engine with the head off with an arrow pointed to the water jacket.

So it appears that the head gasket blew in the same area that the intake manifold is now getting hot (starboard side at the mid point). Any ideas why this might be happening or how to deal with it?

If the bottom photo was shot immediately after removing the head, it shows uneven cooling- the cylinders at the left are burning the fuel more efficiently than the on the right.

The best thing to do when heads are removed is to take them in so they can be checked for cracks. It's not expensive and can eliminate problems later. If the intake is so hot that water boils off on the outside, it's not a good sign.

The MAP sensor ABSOLUTELY needs to be connected. There's no way the fuel/air mixture will be correct and this is extremely important at high RPM and during acceleration. The MAP sensor runs the show once the engine is at more than 2% throttle position and if it's not connected, you will run it lean, causing damage to pistons, cylinders, valves and other parts.

wtrskr

07-24-2011, 03:09 PM

That shot was not right after removing the head. I had started cleaning the head and the two closest to TDC were cleaner because my rags hit those.

Good to know on the Map sensor. I figured it just went to a default value and would be less than optimal but fine in the short term. In that case, it doesn't sound like it would be good to run it if I'm getting a Map sensor code either. The idle is definitely better with it disconnected.

So the head may have a crack stopping the water from flowing properly to the intake manifold? I then wonder where the water would be going? The plugs don't have evidence of water.

When I had everything apart, I didn't inspect the manifold that closely but did at least visually inspect everything else. I also poured solvent into each of the valve chambers to check if the valves were properly seating. I didn't notice any fluid leaking from the valve chambers into the water chambers.

Do you think my next step should be to start tearing into things again and have the head tested by a machine shop or should I do other tests first? If I knew that I wasn't hurting anyting by running it in the meantime I'd wait until the fall.

Thanks.

JimN

07-24-2011, 04:45 PM

That shot was not right after removing the head. I had started cleaning the head and the two closest to TDC were cleaner because my rags hit those.

Good to know on the Map sensor. I figured it just went to a default value and would be less than optimal but fine in the short term. In that case, it doesn't sound like it would be good to run it if I'm getting a Map sensor code either. The idle is definitely better with it disconnected.

So the head may have a crack stopping the water from flowing properly to the intake manifold? I then wonder where the water would be going? The plugs don't have evidence of water.

When I had everything apart, I didn't inspect the manifold that closely but did at least visually inspect everything else. I also poured solvent into each of the valve chambers to check if the valves were properly seating. I didn't notice any fluid leaking from the valve chambers into the water chambers.

Do you think my next step should be to start tearing into things again and have the head tested by a machine shop or should I do other tests first? If I knew that I wasn't hurting anyting by running it in the meantime I'd wait until the fall.

Thanks.

Do you have a vacuum pump for bleeding brakes (or, can you get one)? You can connect it to the MAP sensor hose and pump it to it has a bit of vacuum- if it bleeds down immediately, you have a bad MAP sensor. Did you replace this already? Check the tube from the sensor to the intake manifold, too- does it have liquid in it, or cracks? Does that go to the #8 runner? If so, I would look for a throttle body spacer with a fitting on it that fits the MAP sensor tube. That way, the vacuum reading will be more accurate and it will be drawn from both banks of cylinders, not just one cylinder.

wtrskr

07-24-2011, 06:03 PM

I did already replace the Map sensor. The tube is in good shape with no water or obstructions. The tube goes from the map sensor right to the throttle body so I think it is already getting vacuum from both banks.

I've come to the conclusion that it is probably a problem with the wiring or something else that is messing with the vacuum (maybe the intake manifold temperature issue).

JimN

07-25-2011, 12:06 AM

I did already replace the Map sensor. The tube is in good shape with no water or obstructions. The tube goes from the map sensor right to the throttle body so I think it is already getting vacuum from both banks.

I've come to the conclusion that it is probably a problem with the wiring or something else that is messing with the vacuum (maybe the intake manifold temperature issue).

If it had liquid in it, it would be gas, not water.

I would go back to that dealer and get them to prove what they did "for you". They did squat, IMO. This isn't rocket surgery and they should have been able to fix it, given the chance. If they hooked it up to a diagnostic computer other than a Tech 1, it would have been a laptop and we all know that when a Windows-based computer program is closed, it asks if you want to save it. If ANYONE'S boat is hooked up for diagnostics, that file should be saved, period. This isn't up to anyone's discretion- if a dealer wants to have no proof of what they did when it's time to collect for service preformed, they had better show something for their time, other than someone writing on a work order.

This kind of "service" really pizzes me off and it should do that to every one of you who owns a boat. If you're not satisfied, make the dealer justify their existence. They can't go on forever, expecting people to fork over $100+/hr for labor without results and if I was a service customer, I wouldn't lay down and accept this kind of BS.

I mentioned taking it to someone before- if you want it fixed, go to him. He'll get it done.

wtrskr

07-25-2011, 10:02 AM

Thanks for the input Jim.

I am a little irked at the service as well. My instructions were to hook it up to the computer for diagnostics, to do the necessary inspections to determine why I was getting a Map Sensor code, and to determine why my engine guage showed an overheat. In my opinion they were no help with these issues. They said they solved the Map Sensor issue which they didn't and told me nothing I didn't already know about the overheat.

You did mention a name but I didn't find out what dealer he is with. If you know where he is, can you send me a PM?

Thanks.

Table Rocker

07-26-2011, 01:47 PM

I would get the head Magnafluxed at a machine shop. A cracked head would explain some of your problems and when you have that sorted out, the other stuff will be easier to solve.